2001 x5 wont start all the time

[mgeist]

any ideas or suggestions would greatly be appreciated.

i got an x5 about 5 months ago the last two months it has been acting weird it wont start (dead battery)

i replaced the battery and had the alternator checked nothing.

sometimes the battery will last a day sometimes a week i never know. i dont do anything different when turn it off. ie: turn off radio or air since thats all controlled from the ignition.

mods i have done are add a trailer hitch with bmw oem parts which included the wire harness and control module

added an amp with a remote turnon wire from the bmw amp. i have disconnected both the new amp (i added) and the trailer hitch and same thing sometimes it lasts a day or two others a week.

does anyone have any ideas i can try before taking it to the dealer. dealer wants 180$ an hour to find the problem they said anywhere 1-3 hours then replacing the part or moduel and that could be anywhere from 100 to 1000 but at this point i have no other option or choice however i dont really have the money either but also need a car

thanks!

[Weasel]

Unfortunately it sounds like you have a "parasitic draw" which is when something stays on draining the battery, and is almost always intermittent. As a tech at the dealer, I can tell you that most of the time it takes well over 3 hours to find the problem, sometimes 3 or 4 times that. It can be frustrating

But if you have any mechanical/electrical know how you can try locating it yourself, but you would need to be able to accurately read amperage without disturbing the system via a low current inductive amp clamp. About the only thing I can think of that causes a draw that you can check without testing equipment is the final stage blower resistor. (numerous posts in this forum about it) If your output from your face vents has been at all erratic, that may be your problem. The original one internally shorts and can stay on intermittently with the key off. If you have already had it replaced, then no easy fix. You can tell by pulling it out if it is the new style or old style.

[mgeist]

on another note before this all started it seemed like the fan at the radiator would stay on after i shut off the car but i figured thats because it was just that hot out and needed to cool off. when i turn off the car i do get a little blowing out of the vents nothing like its fully on but almost sounds like its blowing extra air out of the system as if it was pressurised is that what your talking about

[vinuneuro]

There was a TSB for the 01 radio's drawing power with the vehicle turned off. Not sure if such a problem could suddenly appear or is one that would be there from the getgo.

$180/hr is the highest rate I've ever heard (the one we used was $110/hr). Def shop around in terms of that.

[BrianX54.4is]

Originally Posted by mgeist

...when i turn off the car i do get a little blowing out of the vents nothing like its fully on but almost sounds like its blowing extra air out of the system....

Sounds like the Final Stage Resistor for the ventilation blower has failed. It's a very common problem and an easy DIY fix - the failed resistor keeps the blower running slowly even after the ignition is off and thus drains the battery. Search the forum for many posts on this. There is a FSR replacement post on the homepage.

[Weasel]

Yep, when you shut off the key, there should be no airflow from the vents. Sounds like you got lucky and got the easiest parasitic draw out there... Change that FSR and let us know if it solved it!

[mgeist]

thank you for all the help i called the local bmw dealer and he said they have 3 instock i will be picking one up tonight after work and taking my battery out to charge its only a month old and dead because of this problem i will fix everything tomorrow or thurs and let you know if it worked hope it will!

also fyi the part cost $113 at the bmw dealer and it is interchangable between x5 and the 3 series